USGA slows down greens for this year's Open

A stimpmeter calculates speed on a putting green by applying a known force to the ball and measuring the distance traveled.

Green speeds at The Broadmoor's East Course are being maintained at about 10.5 feet - 1.5 feet slower than the greens at Whistling Straits, the site of last year's U.S. Senior Open.

But the speed is unique to each course, said Jeff Hall, the director of rules and competition standards for the U.S. Golf Association.

"There's just too much undulation and movement in those greens," he said. "I'd be scared to death to have it that fast."